| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.9 198/255] loop: Fix occasional uevent drop | Date | Tue, 17 Nov 2020 14:05:38 +0100 |
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From: Petr Vorel <pvorel@suse.cz>
commit c01a21b77722db0474bbcc4eafc8c4e0d8fed6d8 upstream.
Commit 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") causes an occasional drop of loop device uevent, which are no longer triggered in loop_set_size() but in a different part of code.
Bug is reproducible with LTP test uevent01 [1]:
i=0; while true; do i=$((i+1)); echo "== $i ==" lsmod |grep -q loop && rmmod -f loop ./uevent01 || break done
Put back triggering through code called in loop_set_size().
Fix required to add yet another parameter to set_capacity_revalidate_and_notify().
[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/uevents/uevent01.c
[hch: rebased on a different change to the prototype of set_capacity_revalidate_and_notify]
Cc: stable@vger.kernel.org # v5.9 Fixes: 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") Reported-by: <ltp@lists.linux.it> Signed-off-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/block/loop.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -255,7 +255,8 @@ static void loop_set_size(struct loop_de bd_set_size(bdev, size << SECTOR_SHIFT); - set_capacity_revalidate_and_notify(lo->lo_disk, size, false); + if (!set_capacity_revalidate_and_notify(lo->lo_disk, size, false)) + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); } static inline int
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